@cstross @lizmeyer I'm a wee bit younger than you, we didn't have to use slide rules, but we did have books of trig tables that we were allowed to take into exams. Even though I was born after decimalisation I do remember some of the maths books in primary school having problems that required converting between pounds, shillings and pence.
I tried to explain slide rules to one of my younger colleagues. He was very confused.
Sliderules are one of the thing I love about post-WWII classic SF, where the protagonist has faster than light travel, has weird alien friends, but still whips out a slide rule (whilst smoking a cigarette) to work out his plot point of the story.